Injection syringe



@EL ily 393m J. scHoENE M5979 INJECTION SYRINGE Filed Deo. 25, 1935Patented Oct. l, 1935 UNETED STATES anni PATENT QFFIC ApplicationDecember 23, 1933, Serial No.

In Germany December 24, i932 Claims.

My invention relates to improvements in me-dical injection syringes, andrefers more particularly to all-glass syringes. Such syringes, whilehaving nuinerous advantages over al1-metal syringes, also have thedisadvantage that the glass piston of the syring@ is apt to damage thebottom of the syringe cylinder by striking it too hard. Moreoversyringes of the all-glass type share with all other injection syringesthe inherent defect, that even after the syringe has been thoroughlysterilized by boiling, certain lasting forni of bacteria nulliiy theeffect of this sterilization by developing during the periods in whichthe syringe is not in use.

The present invention is intended to obviate these deleterious defectsand aims to produce a better syringe or" this type.

First and foremost, the dome or cone at the working extremity of thepiston of the type of syringe made according to the present invention,is provided with a layer of absolutely pure silver, which in the firstinstance mitigates the shock occurring when the piston reaches thebottom oi the cylinder, while at the same time it frees the interior ofthe syringe of all bacteria or germs, and keeps the interior sterile byreason ci the oligodynarnic action of the silver.

Although for oligodynamic purposes, the silver layer might be situatedat any part of the interior of the syringe, there are special advantagesto be obtained by applying the silver to the deine or cone of theworking face of the piston. is the silver is thus centrally situated,the eligcdynamic action, because the piston is movable within thecylinder, is to a certain extent also made movable, and is able to actat a great inany points. The fixation of the silver layer on the dome ofthe piston may be eiected in any suitable manner.

The dome of the piston may be made electrically conductive by means of asilver solution fused into the same in a known manner and the puresilver being electrolytically deposited thereon.

The appended drawing illustrates two embodiments of the syringe and itsaccessories or component parts.

Fig. l is a vertical longitudinal one of the embodiments.

Fig. 2 is a similar illustration modied syringe.

Figure 3 represents an illustration of a component part, viz. a shockabsorbing device for the piston.

section through of a somewhat (Cl. 12S- 218) Figure l is a detail inperspective of the shock absorbing deviceof Fig. 3.

In Figures and 2 a so called al1-glass syringe is represented, where aindicates the glass syringe cylinder body, b the glass syringe piston, cthe metallic threaded needle carrier fused into the glass syringebottom, d denotes the hollow injection needle, and e in Figure 3 apreferably hexagonal nger support provided on the syringe cylinder.According to the present invention, a comparatively thick layer h (or hin Fig. 3) of silver is fixed or applied to the dome of the piston ofthe syringe in any known manner as by electricity. the elect of thepiston striking the bottom of the syringe body, at the same time keepingor making the interior of the syringe sterile and germ free by means ofits oligodynamic action. In Fig. l the layer h is secured to the pistonby means of a screw i but this may be eliminated as seen in Fig. 2.

As is well known, the oligodynamic action of the pure silver is anaction of the silveroxide produced by the action of the oxygen in theair or by other action and increased or reduced by means of an H2O2ysolution or by means of manganese dioxide or other oxidizationcarriers.

An especially strong, long lasting, resisting and visible oligodynarnicaction is attained, for example, if a somewhat concentrated, neutral,acid or alkaline solution of potassium hyper manganiurn is allowed toact on the silver dome of the piston of the syringe. This causes theformation of a chemical double compound of silver oxide and manganesedioxide (Ag2O 2MnO2). The silver oxide-manganese dioxide formed byalkaline potassium permanganate solution has been found to be especiallysuitable and advantageous. It possesses great resistance in respect toboiling and the action of dry heat as well as against the action ofsulphur ions (sulphuretted hydrogen) and reducing substances, such asnovocaine, or the like, which reduce or nullify the oligodynamic actionof the pure silver, which has been activated and increased by themanganese dioxide.

The manganization of the silvered dome of the syringe piston b by meansof AgzO-2Mn20 is effected in the most simple manner by immersing thedome of the piston for l to 2 hours in, for instance, a glass tube lledwith a solution of potassium permanganate to a height of approximately 1cm.

The protection oered to the syringe by reason of the shock absorbingeiiect of the pure silver This layer of silver mitigates dome of thepiston may be further increased by means of a shock absorbing andbraking device g for the piston b which is Vshovvn assembled in Figs. 2and 3. This device g in the nature of a clip prevents on the one handthe accidental sliding or slipping of the syringe piston by exerting alateral pressure on the periphery of the same and also eliminates th'esharp impact of the piston on the bottom of the syringe, by engaging theabutment f of the same at the very moment of impact or a littlebeforehand. The abutment j on the syringe piston stem strikes upon theshock absorbing piston brake g and thereby slows down the movement ofthe piston.

I claim:

1. An injection syringe having a glass cylinder and a glass piston, anda buffer-like pad of soft metal formed on the Working end only of saidpiston as an extension thereof.

2. An injection syringe having a glass cylinder and a. glass piston, abuffer-like pad of soft metal formed on the Working end of said'pistonas an extension thereof and contacting the cylinder Wall, and said metalhaving sterilizing properties.

3. An injection syringe having a glass cylinder and a glass piston, anda buffer-like pad of pure silver formed on the Working end of saidpiston as an extension thereof and engaging the cylinder Wall.

4. An injection syringe having a glass cylinder 10 and a glass piston, alayer of pure silver on the Working face of said piston, and a coatingfor said silver to augment the sterilizing action of the same.

5. An injection syringe having a glass cylinder 15 and a glass piston, acoating of pure silver on the Working face of said piston, and a coatingof the double compound silver oxide manganese dioxide (Ag2O-2Mn02) onsaid silver.

JOSEF SCHOENE.

